Electrically heated twister



Sept. 22, 1931 E. L; SMITH ET AL ELECTRICALLY HEATED I WISTHR Filed July 31, 1929 2 Sheets-Sheet l INVENTOR.

Sept. 22, 1931. E. L. SMITH ET AL 1,824,307

ELECTRIGALLY HEATED TWI S'I'ER Filed July 51, 1929 2 Sheets-Sheet 2 an i v I W i O I A 7 """10 M @ZZQLZ Y 22, 5; 4 25 e S )0 0 Z6 Fl J 42 INVEJV TOR.

Patented Sept. 22, 1931 UNITED STATES PATENT OFFICE ELMER L. SMITH, OF LONGMEADOW, AND FREDERIC B. FULLER, OI SPRINGFIELD,

MASSACHUSETTS, ASSIGNORS TO PACKAGE MACHINERY COMPANY, OF SPRING- FIELD, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS ELECTRICALLY HEATED TWIBTEB Application filed July 31,

This invention relates to wrapping machinery of the type in which the wrapper is closed about the ends of the article by twlsting.

The object of the invention is to provide mechanism by which a wrapping of this type can be tightly sealed by fusion .of the wax carried by the wrapper. This mechanism is arranged sothat the heat sealing of the wrapper requires no operations in addition to those usual for twisting the wrapper. the twisters being themselves heated. Preferably this is done by forming the twisters of an electrically conductive material of sufiiciently high resistance so that they may be heated by the direct passage of current through them.

The twisting device to be described may be employed with any desired form. of wrapping mechanism, one form to which reference may be made for illustration being shown in the patent to Kempf, 1,226,622, granted May 15. 1917. The present invention being directed to the manner in which the twisters are heated. other details of the mechanism will be omitted from the descrip tion. The two twisters operating on oppo site ends of the article to be wrapped are substantial duplicates of each other and a description of one only will be given.

Referring to the drawings:

Fig. 1 is a side elevation of a twisting head embodying my invention;

Fig. 2 is a longitudinal median section through the twister head:

Fig. 3 is a section on line 33 of Fig. 1;

Fig. 4 is a section taken partially on line 44 of Fig. 3;

Fig. 5 is a section corresponding to a portion of Fig. 2 but showing the twisters closed; and

Fig. 6 is a plan view of the twister head with the parts in the position of Fig. 5.

Each twister head is carried on a bracket 10 forming its attachment to the machine frame and having journaled for rotation therein a member 11 having a T-shaped flange at one end. A pinion 12 fast to one end of this member meshes with a suitable driving gear as' in the Kempf patent referred to above, so that rotation may be im- 1929. Serial No. 882,357.

parted as desired to the member 11 and the twlstlng elements carried by it. The member 11 and a cap 13 secured to it as by screws 14 are formed to provide journals 15 (F g. 3) for a pair of spaced parallel twlster shafts 16 having pinions 17 at their centers. A rod 18 passes through the hollow body of member 11, carrying at one end a grooved head 19 in the nature of a cylindrical rack which engages the pinions 17 to rotate the shafts 16 simultaneously in opp0s 1te directions as the rod is shifted. A spring 20 between the rod and the member 11 bears against a collar 21 on the rod to force the rod to the right in Fig. 2, motion in the other direction, which serves to close the twisters, being accomplished by any suitable mechanism such as is shown for eXam-.

ple in the Kempf patent referred to.

One end of each of the shafts 16 is provided with a twister-wire receiving head 22 having a small cylindrical projection 23. A contact plate 24, conveniently made of brass, is drilled at 25 to receivethese pro jections, and has a recess 26 for receiving a spring 27 seated in a similar recess 28 in a block 29. This block is secured as by screws to an insulating member 30 held by screws 31 to the member 11.. The contact plate serves to connect the two twister shafts to the grounded side of an electrical heating circuit in a manner to be described later.

Theopposite ends of the shafts 16 are provided with insulating bushings 35 upon which are carried metallic twister-wire couplings 36, 37 These two couplings are substantial duplicates of each other, but are constructed so that their extending portions 38 overlap as in Fig. 3 to conserve space. The

- portions 38 are split as at 39 (Fi 1), the portions thus partially separated eing drawn together by screws 40 so that the couplings and the insulating bushings, which are preferably also split, are firmly clamped to the shafts 16. Each of the couplings 36, 37 is provided with a small cylindrical projection 41 for reception in a hole in a contact plate 42 similar to the plate 23 and similarly spring pressed by a spring 43 carried in a block 44.

The twister-wire heads 22 and the twisterwire couplings 36, 37 are thus electrically insulated from one another. From each of the heads 22extends a twister wire which is bent intogeneral U-form and terminates in the twister-wire coupling which is carried on the same shaft from which the wire started. Preferably the central section 46 of each wire is formed of a high resistance wire such as nichrome secured to the body of the twisterwire as by sleeves 47 so that the twister may be of substantial construction and still have that portion in contact with the paper warmed by the passage of a relatively moderate electric current. The two U-shaped wires are preferably so spaced and positioned that they maycross eachother as in the Kempf patent. Contact between them need not, however. be guarded against, as opposed portions of the two wires are always at equal electrical potentials.

Since during the operation of the twisters they are in rotation, it is necessary to supply some means, as a slip ring connection. for joining the parts described to a suitable source of electric current. In the embodiment described, the insulating member 30 has a cylindrical extension 50 (Fig. 2) upon which are mounted a pair of slip rings 51 separated by insulating washers 52 (Fig. 1).

"One of these rings is. connected by a wire 53 (Fig. 3) and a screw 53' (Fig. 1) to the contact plate 24 and the other by a wire 54 and a screw 54' to the contact plate 42. The supporting bracket 10 has an insulating block 55 attached to it in which a pair of carbon or copper brushes 56, one foreach of the slip rings 51, are slidingly mounted. Springs 57 constantly urge the brushes towards the slip rings. Flexible wires 58 run from each of the brushes to binding posts 59 from which connection may be made to any suitable electrical current supply, indicated conventionally in Fig. 2 as a transformer 60 provided with a control rheostat 61.

The manner of use of the device should be apparent from the above description. Electriccurrent is continuously supplied to the slip rings and from them passes through the contact plates and through the two twister wires in multiple. The high resistance portion of this circuit (i. e.. the active portion of the twister wires) is thereby heated to a temperature suitable for sealing the Wax paper. The temperature can readily be adjusted by varying the current flowing through the circuit by means of the rheostat 61. When the twister wires close upon the ends of the'wax paper wrapper they will twist the ends in the usual manner due to their rotation. but in addition the heat supplied through the wires will melt the wax and will cause the twisted naperto be permanently sealed. Since the twisters do not come into contact with the article being wrapped, this heat sealing process may be used with articles which would be injured by the usual methods of sealing by heat. Furthermore, the application of heat to the ends of the wrapper during the twisting operation serves to increase in a substantial manner the tightness with which the paper is drawn around the article. Changes in the mechanical details may of course be made without departing from .the invention as pointed out by the claims.

Claims: Y

1. In a wrapping machine, a head, a air of parallel shafts journaled in the hea a coupling mounted on each of the shafts but electrically insulated therefrom, a pair of U-shaped twister wires, each having one end supported by and electrically connected to 7 one of the shafts and the other end supported by and electrically connected to that coupling mounted on said shaft, means for rotating said shafts simultaneously in opposite directions to open and close the twisters, and means for connecting the shafts and the couplings respectively to the opposite poles of a source of electric current.

2, In a wrapping machine,'a head, a pair of shafts journaled in the head, a pair of U-shaped twister wires one mounted on each of the shafts and with the two ends of each -wire electrically insulated from each other,

means to rotate the shafts simultaneously in opposite directions to open and close the twisters, and means for connecting opposite ends of each twister wire to the opposite poles of a source of electric current.

.3. In a wrapping machine, a rotatable head, a pair of parallel shafts journaled in the head, a coupling mounted on each of the shafts but electrically insulated therefrom, a pair of U-shaped twister wires each having one end supported by and electrically conneoted to one of the shafts and the other end supported by and electrically connected to that coupling mounted on said shaft, means for rotating said shafts simultaneously in opposite directions to open and close the twisters, a pair of slip rings carried by the head so as to be electrically insulated from each other, electrical connections between the shafts and one of said slip rings and between the couplings and the other of said slip rings, and a pair of relatively stationary brushes making contact respectively with the two slip by the head so as to be electrically insulated from each other, electrical connections between one end of each mm and one of said signatures.

ELMER L. SMITH. FREDERIC B. FULLER. 

